OptionsResponse encapsulates the DAV:options-response element
present in the response body of a successful OPTIONS request (with body).
The DAV:options-response element is defined to have the following format.

<!ELEMENT options-response ANY>
ANY value: A sequence of elements

Please note, that OptionsResponse represents a simplified implementation
of the given structure. We assume, that there may only entries that consist
of a qualified name and a set of href child elements.

addEntry(String localName,
Namespace namespace,
String[] hrefs)
Add a new entry to this OptionsResponse and make each
href present in the String array being a separate DAV:href
element within the entry.